Medical imaging instruments, such as ultrasound probes, are frequently used by doctors and other medical professionals to conduct non-invasive examination of humans and animals. Imaging instruments, such as ultrasound probes, can be effectively used to examine internal tissue that is not readily examined using normal visual and tactile examination. Kidney stones, tumors, cysts, etc. are all amenable to examination using these medical imaging instruments. In addition, medical imaging instruments are well suited to examination of a growing fetus and to determination of the health of the fetus and to making medical diagnosis' to improve the fetus' health.
Traditionally, the position of many medical imaging instruments, including ultrasound probes, has often been controlled by having the medical practitioner hold the imaging instrument in one or both of his or her hands. In this manner, the medical practitioner manually guides the instrument. Such methods are suitable for many medical procedures, but also pose significant shortcomings in other procedures. One problem associated with manually holding the probe is that the probe can fully occupy one hand of the medical practitioner, thereby making it more difficult to perform ancillary medical procedures, such as removal of a biopsy sample, or even the taking of notes or manipulating the controls of the imaging instrument. Another significant problem associated with holding the probe is that it can be difficult to hold the probe steady, and thus it is difficult to "fine tune" the probe adn direct the imaging field to precise locations in a patient. This fine tuning of the probe location can be particularly important when very localized tissue sampling or medical procedures are being performed, such as during surgical procedures.
In order to address this problem, imaging instrument holding devices have been developed. Unfortunately, existing devices are limited in their effectiveness. For example, Ota et al. have patented a three-dimensional medical locating apparatus (U.S. Pat. No. 5,257,998). Unfortunately, the Ota apparatus is limited to positioning of the instrument in a spherical region about a target point within a patient. Similarly, Winston Barzell and Willet Whitmore of Sarasota, Fla. have developed an imaging positioning system that provides adjustment of an imaging instrument. Unfortunately Barzell and Whitmore's device does not provide for easy and intuitive positioning of an imaging instrument.